Post on 25-Dec-2015
Clean Air MarketsProgram Data
UC Energy Institute
University of California at Berkeley
November 10, 2003
Martin Husk
Overview
How emissions and heat input are monitored
Monitoring system certification requirements and testing
On-going quality assurance testing
Contents of the Electronic Data Report
Overview
Quality assurance standards
Data availability
Uses of the data
Questions and answers
How Emissions are Monitored
Identify which pollutants require monitoring
Identify which other parameters may require monitoring
Acid RainProgram (ARP)
SO2 mass emissions (lb/hr) NOX emission rate (lb/mmBtu) CO2 mass emissions (tons/hr) Heat Input (lb/mmBtu)
NOx Budget TradingProgram (NBTP)
NOX mass emissions (lb/hr) Heat Input (lb/mmBtu)
Acid RainProgram
SO2 mass emissions (lb/hr) NOX emission rate (lb/mmBtu) CO2 mass emissions (tons/hr) Heat Input (lb/mmBtu)
NOx Budget TradingProgram
NOX mass emissions (lb/hr) Heat Input (lb/mmBtu)
Stack Flow Rate Stack Moisture
Opacity Fuel Flow Rate
How Emissions are Monitored
Select the most appropriate monitoring type:
Continuous Emissions Monitoring System (CEMS)
Appendix D and E
Low Mass Emissions Methodology (LME)
Predictive Emissions Monitoring System (PEMS)
Continuous Emissions Monitoring System (CEMS)
Part 72 defines it as equipment used to “sample, analyze, measure and provide…a permanent record of emissions.”
CEMS consists of monitors installed in stacks and/or ducts, and a Data Acquisition and Handling System (DAHS).
Measure emissions and heat input every 15 minutes.
Types of CEMS Conventional Extractive (Wet or Dry Basis Measurement)
Hot Wet - Wet Basis
Cool Dry with condenser near the CEMS Shelter - Dry Basis
Cool Dry with condenser at the probe - Dry Basis
Dilution Extractive (Wet Basis Measurement)
In Stack Dilution
Out of Stack Dilution
In-situ (Wet Basis measurement in the stack)
Point
Path
Conventional Extractive CEMS
Conventional Extractive Systems Representative sample of the flue gas is continuously
withdrawn from the stack, transported to a CEMS shelter and analyzed
Components of an extractive system Probe
Sample lines
Filters
Moisture removal system
Pump
Analyzer
Extractive systems usually make measurements on a dry basis
Dilution Extractive CEMS(wet basis)
Flue gas is diluted with clean dry air to lower the dew-point of the sample
Eliminates the need for Heated sample lines
Moisture removal system
In Stack Dilution Critical Orifice is in the probe
Sample Temperature is Stack Temperature
Quicker response than out of stack dilution
No temperature controls to maintain
In-Situ CEMS Point
Electro-optical, or
Electrochemical sensor
Measurement over short distant (~cm)
Path Light or sound is
transmitted across the stack
The interaction with the stack gas is related back to a gas characteristic
In-Situ CEMS
Typical Applications: Opacity Measurement
Path - Light
Stack Flow Point - Differential Pressure (s-type Pitot)
Path - Ultra-sonic (sound waves)
Alternatives to CEMS CEMS are required except for cases that qualify to
use the following options: Appendix D - SO2 and Heat Input Monitoring Options
Appendix E - NOx Emission Rate Estimation Procedures
Low Mass Emissions - Estimation of SO2, NOx, and CO2 emissions and total heat input using:
Default or site-specific emission factors, and
Max. unit heat input or actual heat input from fuel usage data
Predictive Emissions Monitoring - Estimation of NOx emissions using
CEMS validation of estimation procedures
Appendix D Applicability
May be used in lieu of SO2 and/or flow and diluent monitors to determine hourly SO2 mass emissions and/or heat input rate
Gas and Oil fired units only
Principle: Fuel Flow Rate * Sulfur content = SO2 emissions
Fuel Flow Rate * Gross Calorific Value (GCV) = Heat Input
Requires Monitoring of: Hourly Fuel Usage (fuel flowmeters)
GCV and Sulfur content of the fuel (default SO2 emission rates allowed for gaseous fuels)
Appendix E
May be used in lieu of a NOx-diluent CEMS for determining hourly NOx emission rate (lb/mmBtu)
Applicable only to Gas and Oil-Fired Peaking Units
If you qualify for Appendix E, you must use Appendix D to determine heat input rate
Appendix E Units that hold peaking status must continue to meet the
peaking unit definition from year-to-year
If a unit fails to meet the criteria it must install & certify a NOx CEM by December 31 of the year after the year for which the criteria are not met
A unit may then only re-qualify by providing three consecutive years (or ozone seasons) of qualifying capacity factor data
How Appendix E Works The average NOx emission rate (lb/mmBtu) is determined from fuel
specific NOx emission rate testing at four, equally spaced load levels
The hourly heat input rate is determined using the fuel flow monitoring procedures of Appendix D
The NOx Emission Rate is plotted vs. Heat Input Rate to create a baseline correlation curve
The baseline correlation curve is programmed into the DAHS and is used to determine the hourly NOx emission rate corresponding to the heat input rate for each hour of operation
NOx Correlation Curve Segments
0.000
0.050
0.100
0.150
0.200
0.250
0.300
0 200 400 600 800 1000 1200 1400
Heat Input Rate (mmBtu/hr)
NO
x E
mis
sio
n R
ate
(lb
/mm
Btu
)
Operating Level 1
Operating Level 2
Operating Level 3
Operating Level 4
Segment 1
Segment 2
Segment 3
Segment 4
Low Mass EmissionsMethodology (LME)
Procedure that may be used in lieu of CEMS and the Appendix D and E methodologies to report SO2, NOx, and CO2, emissions and Heat Input
Gas-fired and oil-fired units only
DAHS is not required -- EDR reports can be generated using EPA’s MDC (or any other) software
Emissions limitations Annual NOx limit: NOx < 100 tons/year
Ozone season NOx limit: NOx < 50 tons/control period
SO2 limit < 25 tons/year (ARP units only)
Predictive EmissionsMonitoring Systems (PEMS)
May be used in lieu of a NOx monitoring system
Consists of PEMS software and a DAHS
Software “predicts” what the NOx emissions will be for each hour, based on comparison testing with CEMS
Monitoring System CertificationRequirements and Testing
CEMS Testing: Gas Monitors
7-day calibration error check
Linearity check
Cycle time test
RATA/Bias test
Flow Monitors 7-day calibration error check
3 load RATA and Bias tests
7-day Calibration Error Test
Measure calibration error of each pollutant monitor while unit is combusting fuel once each day for 7 consecutive operating days
Linearity Check
3 point check of linearity of each pollutant monitor while unit is combusting fuel at conditions of typical stack temperature and pressure Low (20 - 30% of span)
Mid (50 - 60% of span)
High (80 - 100% of span)
Cycle Time Test
Determine time it takes for 95% of step change to occur going from:
a stable zero gas value to stack emission value, and
a stable high calibration gas value to stack emission value
The cycle time is the slower of the two responses
Relative Accuracy TestAudit (RATA)
Compares CEMS measurements to appropriate EPA reference method
Conduct a minimum of 9 valid runs
May discard up to 3 runs but must report all runs performed
Recommended that RATA not be commenced until completion of other required certification tests
Bias Test
Statistical test that evaluates RATA data to determine if a low bias exists in the CEMS measurements, and to determine need for calculating a Bias Adjustment Factor (BAF)
Monitoring System CertificationRequirements and Testing
Appendix D Fuel Flowmeter Accuracy Test is generally required
annually
Fuel Flow-to-Load Ratio or Gross Heat Rate-to-Load evaluation may be used as a quarterly check of the fuel flowmeter accuracy
Can be used to extend the interval between fuel Flowmeter Accuracy tests to up to 5 years
Monitoring System CertificationRequirements and Testing
Appendix E:
The NOx emission rate testing must be repeated once every 5 years
Appendix D fuel flowmeter QA required
On-going Quality AssuranceTesting for CEMS
Daily Calibration Error Test
Daily Interference Check (flow monitors only)
Quarterly Linearity Check
Quarterly Flow-to-Load Ratio (flow only)
Quarterly Leak Checks (differential pressure flow systems)
Relative Accuracy Test Audit (RATA)
Bias Test (SO2, NOx, and flow monitors only)
Calibration Error Checks Measure the calibration error of each pollutant monitor while the unit is
combusting fuel by injecting a known calibration gas into the system at the point of sample collection
Zero Gas (0 - 20% of span)
High Gas (80 - 100% of span) or Mid Gas (50-60%)
For initial certification, a CEMS must meet a tight calibration standard for 7 consecutive operating days
For ongoing QA, daily calibration error checks are required
Interference Check
Daily QA check required for stack flow monitors
Diagnostic check that confirms that monitor is ready for use
Flow-to-Load Ratio Test
Quarterly evaluation of a stack flow monitor’s accuracy
A baseline comparison of the hourly ratio of flow rate to unit load (Q/L) and a reference Q/L determined during the last flow RATA test
Leak Check
Quarterly QA check for differential pressure type flow monitors
Confirms the absence of leaks in the connections and lines
SO2 Monitoring
METHOD SO2 (Tons)AMS 106 0.0%APPD 183,429 1.8%CEM 10,028,755 95.8%F23 259,847 2.5%LME 6 0.0%
Total 10,472,142
SO2 Methodology by # of Units
APPD
59%
CEM
36%
AMS
0%F23
3%
LME
2%
AMS APPD CEM F23 LME
SO2 Methodology by Emissions
CEM96%
APPD2%
LME0%
F232%
AMS0%
AMS APPD CEM F23 LME
METHOD UnitsAMS 2 0%APPD 1810 58%CEM 1127 36%F23 106 3%LME 61 2%
Total 3106
NOx Monitoring
NOx Methodology by # of Units
CEM87%
LME4%
AMS0%
APPE9%
AMS APPE CEM LME
METHOD UnitsAMS 3 0.1%APPE 293 8.6%CEM 2966 87.4%
LME 131 3.9%
Total 3393
NOx Methodology by Emissions
CEM
100%
AMS
0%
LME
0%APPE
0%
AMS APPE CEM LME
METHOD NOx TonsAMS 463.884 0.0%APPE 5643.801 0.1%CEM 4944886 99.9%
LME 758.286 0.0%
Total 4951752
NOx Methodology by Emissions
CEM100%
APPD0%
LME0% AMS
0%
AMS APPD CEM LME
Contents of theElectronic Data Report (EDR)
EDR required each quarter or during Ozone Season
Collection of EDR data is fundamental to verifying program
EDR Files contain the following items:
Facility information
As-monitored emissions data (measured in ppm)
Contents of the ElectronicData Report (EDR)
EDR Files contain the following items:
Operational data (operating time, heat input)
Calculated mass emissions and heat input data
Monitoring Plan
Quality assurance/test data
Certification records
Quality Assurance Standards
Extensive QA process for EDR data
“Instant Feedback” based on ETS data checking
Audit process feedback provided after all data are submitted
Quality Assurance Standards
ETS data checking in two stages
File Summary: checks general format and integrity of file.
File Content: checks the data within the file recalculate all hourly data
hourly sums vs. aggregates
monitoring plan checks
Over 150 checks performed on EDR data
Quality Assurance Standards
Audit Process is run to evaluate the monitoring plan, and QA and test data
Process is run after the end of each reporting period
Feedback Emailed to sources
Resubmissions of EDR data often required
Data Availability
EDR data are submitted during the month after each calendar quarter
“As reported” EDR files posted on the CAMD web site 20 days after the end of each reporting period
Summary Emissions Reports posted on CAMD web site 20 days after the end of each reporting period
Data Availability
Annual and Ozone Season data posted on Data and Maps web site page after program compliance is determined
Hourly, monthly and quarterly posted on Data and Maps web site page after program compliance is determined
Resubmitted EDR files are updated to the Data and Maps page each quarter
Uses of the Data
EPA uses of the data
Annual Acid Rain Program and NOx Budget Program Compliance
Public access through web site
Provide to other government agencies
Compare to other agencies’ data
Uses of the Data
Your uses of the data
What EPA data do you use?
How do you access the data?
What analyses are performed based on EPA data?
Are there other pieces of data you need for your analyses?
Questions and Answers